You very likely have keratosis pilaris, a
hereditaryHereditary amyloidosis
Pseudohypoparathyroidism condition. You can smooth the bumps out to some extent with some of the methods you've already used, such as alpha-hydroxy moisturizers and exfoliation. Perhaps you didn't use them long enough, or maybe you assumed they would make the problem go away forever, which it won't. (That's heredity for you.)
I advise you to check with your dermatologist about the use of stronger exfoliating techniques.
Take care.
Dr. Rockoff